Eye surgical instruments with optical fibers for lighting the interior of the eye are known from practice. Multiple fibers in a bundle of fibers are then connected to one light source. Each fiber has a stop, so that an insertion part of the respective fiber, which is to be placed in the eye, can extend a fixed, predetermined distance into the eye. The known fibers are surrounded up to the stop with a sleeve to prevent light exiting. The stop and the sleeve are fixed at a fixed distance to the end of the fibers. In this way, the length of the insertion part will not change while it is fixed in the eye.
One of the disadvantages of this bundle of fibers is that the light often cannot be directed to the desired location in the eye in a precise manner.
This disadvantage and other disadvantages can be counteracted by providing an eye surgical instrument comprising at least one optical fiber for lighting the interior of the eye, which at least one optical fiber is provided at a free end thereof with a light exit and with a stop situated at a distance from the free end, which stop defines an insertion part situated between the end and the stop, and at another end is connectible to a light source, while the stop forms a separate element which is arranged so as to be slidable along the at least one fiber.
With the slidable stop, the length of the insertion part can be adjusted in a simple but precise manner and the light in the eye can be directed better to the desired location in the eye.
The invention is based on the insight that the slidable stop enables more precise directing, while surprisingly, precisely by virtue of the simple and controlled adjustability of the projecting part, a desired safety is maintained.